The present invention relates to storage of bulk commodities in loose or bagged form and, more particularly, to the long term storage of bulk commodities under a controlled environment.
Bulk storage of commodities such as, coffee, grains, fruits cocoa, and the like are subject to deleterious effects including extensive loss caused by insects in the commodity during storage, the effects of oxidation during storage produced, for example, by the growth of micro-organisms and/or fungi in the commodity and other impacts on the quality, nutrition purposes, safety, purity, appearance, taste, aroma and freshness of the commodity.
A well-known method for long term storage of a bulk commodity utilizes a hermetically sealed enclosure formed from a flexible, low gas-permeability set material employing the slow depletion of oxygen by respiration of live insects present in the commodity, and by the commodity itself. However, this process takes significant time and relies on a significant level of infestation to deplete the oxygen in addition, after the insects die, the oxygen level gradually rises due to infiltration thereby permitting various oxidation effects in the stored commodity.
Vacuum sealing of bulk commodities also has been rejected because of the perceived need for rigid and expensive pressure vessels.
It is accordingly, a general object of the invention to provide a method for long term storage of bulk commodities that obviates the above problems.
In the present invention, to insure the rapid kill of biological contaminant(s), such as insects, as well as to protect the commodity from oxygen-effected deterioration such as the growth of fungi and micro-organisms, a oxidation, the commodity is sealed within the enclosure after which the atmosphere therein is evacuated to establish a vacuum. The vacuum is maintained during at least a portion of the long term storage of the bulk commodity. Handling of the bulk commodity it achieved through selectively opening and closing an airtight seal in the enclosure formed by the flexible, low gas-permeability sheet material.